JP2018060649A - Light emitting device and luminaire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emitting device having a small size and a lighting device including the light emitting device, which can brightly illuminate a specific range of an irradiated surface. A light emitting device includes a light emitting element and a luminous flux control member. The light beam control member includes a first incident surface that incidents light emitted from the light emitting element and a first total reflecting surface that totally reflects a part of the light incident from the first incident surface, and faces the light emitting element. The first convex portion arranged in the light emitting element, the second incident surface for incident light emitted from the light emitting element, and the second total reflecting surface for totally reflecting at least a part of the light incident from the second incident surface, and The second convex portion arranged so as to surround the first convex portion, the light incident from the first incident surface, the light reflected by the first total reflecting surface, the light incident on the second incident surface, and the second total reflecting surface. Has an exit portion arranged on the opposite side of the first convex portion and the second convex portion, which emits the reflected light. The luminous flux control member and the light emitting element have a predetermined shape. [Selection diagram] Fig. 4

Description

  The present invention relates to a light emitting device having a light emitting element and a light flux controlling member for controlling the light distribution of light emitted from the light emitting element, and an illumination device using the light emitting device.

  For the purpose of energy saving and space saving, a light emitting diode (hereinafter also referred to as “LED”) is used as a light source of various light emitting devices. For example, LEDs are also used as light sources in light emitting devices for spot light irradiation used for indoor lighting, store lighting, and the like. A conventional light emitting device for spot light irradiation includes, for example, a substrate, a plurality of LEDs (light emitting elements) disposed on the substrate, and a plurality of lens bodies (light flux controlling members) disposed to face the LEDs. And had.

  In recent years, a chip-on-board (COB) type light emitting device in which a plurality of LED chips are mounted on one substrate has been put into practical use. According to the COB light emitting element, there is an advantage that a sufficient amount of light can be obtained with a single light emitting element, and an LED having a large light emitting area, such as a COB light emitting element, can be used for a light emitting device for spot illumination. It is being considered.

  As shown in FIG. 1, in the light emitting device 800 described in Patent Document 1, a light emitting element 810 having a size with a light emitting surface that cannot be regarded as a point light source such as a COB method, and the light emitting element 810 emits light. A light beam control member 820 for controlling the light distribution characteristics of the emitted light. The light flux controlling member 820 includes an incident concave portion 821 into which light emitted from the light emitting element 810 is incident, a total reflection surface 822 that reflects a part of the light incident from the incident concave portion, and the light incident from the incident concave portion 821 and all And an exit recess 823 for emitting the light reflected by the reflecting surface 822. In the light emitting device 800, the light distribution of the light emitted from the light emitting element 810 is controlled by the light flux control member 820. Specifically, the light emitted from the light emitting element 810 is emitted with a narrow-angle light distribution from the light emitting recess 823 of the light flux controlling member 820 and its periphery.

JP 2007-265722 A

  Here, in the light emitting device for spot light, it is required to brightly illuminate only a specific range of the irradiated surface. However, in an LED having a large light emitting area as in the COB method, it is difficult to collect light emitted from any position on the light emitting surface of the LED in a specific range by controlling it with a light flux controlling member combined therewith. For example, in a light beam control member used in a general light emitting device, light emitted from the light emission center of the light emitting element, light emitted from around the light emission center, light emitted from the end of the light emitting element, etc. It was difficult to control. Further, according to the light flux controlling member 820 of the light emitting device 800 described in Patent Document 1, although the light can be condensed to some extent, the area of the total reflection surface 822 needs to be considerably larger than the area of the light emitting surface of the light emitting element 810. In addition, there is a problem that the size of the light emitting device 800 tends to increase.

  The present invention has been made in view of this point. That is, an object of the present invention is to provide a light emitting device that can illuminate only a specific range of a surface to be irradiated brightly and that has a relatively small size, and an illumination device using the light emitting device.

The light-emitting device of the present invention includes a light-emitting element, a light flux control member that makes the light emitted from the light-emitting element incident on the optical axis of the light-emitting element and controls the light distribution of the incident light to be emitted. ,including. The light flux controlling member includes a first incident surface on which light emitted from the light emitting element is incident, and a first total reflection surface that totally reflects part of the light incident from the first incident surface, and the light emission A first convex portion disposed so as to face the element, a second incident surface on which the light emitted from the light emitting element is incident, and a first part that totally reflects at least a part of the light incident from the second incident surface. A second convex portion including two total reflection surfaces and arranged to surround the first convex portion, light incident from the first incident surface, light reflected by the first total reflection surface, and the first And a light emitting portion disposed on the opposite side of the first convex portion and the second convex portion, which emits light incident on the two incident surfaces and light reflected by the second total reflection surface. The first incident surface is disposed at a position facing the light emitting element so as to intersect a central axis of the light flux controlling member, and the first total reflection surface surrounds the central axis of the light flux controlling member, and the center The distance from the axis is constant, or the distance from the central axis is gradually increased from the light emitting element side to the emitting part side, and the second incident surface is the central axis of the light flux controlling member Is disposed such that the distance from the central axis is constant, or the distance from the central axis gradually decreases from the light emitting element side toward the emitting portion side, and the second total reflection surface is It surrounds the central axis of the light flux controlling member, and is arranged such that the distance from the central axis gradually increases from the light emitting element side toward the emitting part side. In the light emitting device, in a cross section passing through the central axis of the light flux controlling member, the width of the light emitting surface of the light emitting element facing the light flux controlling member is z, and the maximum width of the first convex portion in the direction orthogonal to the central axis. A, the minimum distance between the first convex portion and the second convex portion, e, the central axis from the light emitting surface of the light emitting element or its extension line to the light emitting portion side end of the first total reflection surface The distance in the direction is b, the width of the first incident surface in the direction perpendicular to the central axis is c, the distance between the first incident surface and the light emitting surface of the light emitting element is d, and the first total reflection surface is When the height in the central axis direction is h and the height in the central axis direction of the second total reflection surface is i, the following expressions (A) to (E) are satisfied.
(A) 0.15z ≦ (a + 2e) ≦ 1.7z
(B) b ≧ z
(C) 0.15z ≦ c <z
(D) 0 <d ≦ 0.7b
(E) i> h

  The illumination device of the present invention includes the above-described light emitting device and an irradiated member that is irradiated with light emitted from the light emitting device.

  The light-emitting device of the present invention can brightly illuminate only a specific range of the irradiated surface, and can reduce its size.

FIG. 1 is a diagram illustrating a configuration of a conventional light emitting device described in Patent Document 1. In FIG. 2A is a plan view of the light-emitting device according to Embodiment 1, FIG. 2B is a front view, FIG. 2C is a bottom view, FIG. 2D is a perspective view, and FIG. 2E is A shown in FIG. It is sectional drawing of a -A line. FIG. 3 is a cross-sectional view of the light flux controlling member of the light emitting device according to Embodiment 1. 4 is a cross-sectional view of the light-emitting device according to Embodiment 1. FIG. FIG. 5 is a diagram illustrating simulation results of light intensity distributions of the light-emitting device for verification and the light-emitting device for comparison. FIG. 6 is a cross-sectional view of a light-emitting device for verification. FIG. 7 is a diagram illustrating simulation results of light intensity distributions of the light-emitting device for verification and the light-emitting device for comparison. FIG. 8 is a diagram illustrating simulation results of the light intensity distribution of the light-emitting device according to Embodiment 1 and the comparative light-emitting device. FIG. 9 is a diagram illustrating simulation results of the light intensity distributions of the light-emitting device according to Embodiment 1 and the comparative light-emitting device. 10A is an optical path diagram of the light emitting device according to Embodiment 1, and FIG. 10B is an optical path diagram of a comparative light emitting device. 11A is an optical path diagram of the light emitting device according to Embodiment 1, and FIG. 11B is an optical path diagram of a comparative light emitting device. 12A is an optical path diagram of the light emitting device according to Embodiment 1, and FIG. 12B is an optical path diagram of a comparative light emitting device. 13A is a plan view of the light emitting device according to Embodiment 2, FIG. 13B is a front view, FIG. 13C is a bottom view, FIG. 13D is a perspective view, and FIG. 13E is A shown in FIG. It is sectional drawing of a -A line. FIG. 14 is a cross-sectional view of the light flux controlling member of the light emitting device according to Embodiment 2. 15A is a plan view of the light-emitting device according to Embodiment 3, FIG. 15B is a front view, FIG. 15C is a bottom view, FIG. 15D is a perspective view, and FIG. 15E is an A view shown in FIG. It is sectional drawing of a -A line. FIG. 16 is a cross-sectional view of the light flux controlling member of the light emitting device according to Embodiment 3. FIG. 17 is a cross-sectional view of a light flux controlling member according to a modification of the light emitting device of the second embodiment. FIG. 18 is a schematic diagram of a lighting apparatus according to an embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Embodiment 1]
FIG. 2 shows a light-emitting device 100 according to Embodiment 1 of the present invention. 2A is a plan view of the light emitting device 100, FIG. 2B is a front view of the light emitting device 100, FIG. 2C is a bottom view of the light emitting device 100, and FIG. 2D is a perspective view of the light emitting device 100. 2E is a cross-sectional view taken along line AA shown in FIG. 2A.

  As illustrated in FIG. 2E, the light emitting device 100 includes a light emitting element 110 and a light flux controlling member 120. The light emitting element 110 may be an element having a light emitting surface such as a light emitting diode (LED), and the type thereof is not particularly limited. However, from the viewpoint of sufficiently obtaining the effects of the present invention, a light emitting element having a large light emitting surface area is preferable, and a COB type LED is particularly preferable.

  The shape of the light emitting surface (hereinafter also simply referred to as “light emitting surface”) facing the light flux controlling member 120 of the light emitting element 110 is not particularly limited, and may be any shape, but is usually circular. The area of the light emitting surface of the light emitting element 110 is appropriately selected according to the use of the light emitting device 100 and the like.

  On the other hand, the light flux controlling member 120 is a member for controlling the orientation of the light emitted from the light emitting element 110. In the light emitting device 100, the light flux controlling member 120 is positioned with the light emitting element 110 by a support portion (not shown), and the central axis CA is disposed so as to coincide with the optical axis LA of the light emitting element 110.

  The material of the light flux controlling member 120 is not particularly limited as long as it can pass the wavelength of light emitted from the light emitting element 110. Examples of the material of the light flux controlling member 120 include light transmissive resins such as polymethyl methacrylate (PMMA), polycarbonate (PC), and epoxy resin (EP), and glass. The light flux controlling member 120 is formed by, for example, injection molding.

  FIG. 3 shows a cross-sectional view of the light flux controlling member 120 of the present embodiment, and FIG. 4 shows a cross-sectional view of the light emitting device 100 of the present embodiment. 3 and 4 are both cross-sectional views passing through the central axis CA of the light flux controlling member 120 (LA of the light emitting element 110). In these drawings, hatching is omitted to clearly show the structure of the light flux controlling member 120.

  As shown in FIGS. 3 and 4, the light flux controlling member 120 includes a first convex portion 121 disposed so as to face the light emitting element 110 and a second convex portion disposed so as to surround the first convex portion 121. And a light emitting portion 123 disposed on the opposite side of the first convex portion 121 and the second convex portion 122, that is, on the opposite side of the light emitting element 110.

  The first convex portion 121 is a columnar or substantially truncated cone portion disposed so as to protrude toward the light emitting element 110, and the central axis of the first convex portion 121 is the central axis CA of the light flux controlling member 120. It matches. The first convex portion 121 includes a first incident surface 121a that forms a top surface of a cylinder or a truncated cone, and a first total reflection surface 121b that forms a side surface of the column or the truncated cone.

  The first incident surface 121 a is a surface that is disposed at a position facing the light emitting element 110 and allows light emitted from the light emitting element 110 to enter. The first incident surface 121a is a circular plane centered on the central axis CA, and is arranged to intersect the central axis CA perpendicularly.

  On the other hand, the first total reflection surface 121b is a surface for reflecting a part of the light incident from the first incident surface 121a toward the emission part 123 side of the light flux controlling member 120. Note that the “total reflection surface” in the present specification means a surface intended to totally reflect light reaching the surface of the light emitted from the light emission center of the light emitting element 110. Although most of the light emitted from a position other than the emission center of the light emitting element 110 is totally reflected on the total reflection surface, the total reflection surface is not a surface intended to totally reflect all the light. The first total reflection surface 121b is a rotationally symmetric surface centered on the central axis CA and disposed so as to surround the central axis CA of the light flux controlling member 120. The distance between the first total reflection surface 121b and the central axis CA may be constant, or may gradually increase from the light emitting element 110 side toward the emission part 123 side of the light flux controlling member 121. Note that the shape of the first total reflection surface 121b in the cross section passing through the central axis CA of the light flux controlling member 120 may be a curved line convex outward (side away from the central axis LA) or a straight line. In the present embodiment, it is a straight line.

  The second convex portion 122 is an annular portion disposed so as to surround the first convex portion 121 and project toward the light emitting element 110 side. The 2nd convex part 122 contains the 2nd entrance plane 122a which constitutes the inner side of a ring, and the 2nd total reflection surface 122b which constitutes the outside side of a ring. The second incident surface 122a and the second total reflection surface 122b may be directly connected on the light emitting element 110 side or may be connected via another surface. However, if the area of the second convex portion 122 other than the second incident surface 122a and the second total reflection surface 122b is increased, the size of the light emitting device 100 is increased, and the light distribution characteristics are deteriorated. Therefore, it is preferable that the area of the surface connecting the second incident surface 122a and the second total reflection surface 122b is small.

  Here, the second incident surface 122a is a surface on which light emitted from the light emitting element 110 is incident, and is rotationally symmetric about the central axis CA, which is disposed so as to surround the first total reflection surface 121b. Surface. The distance between the second incident surface 122a and the central axis CA may be constant, or may gradually decrease from the light emitting element 110 side toward the light exiting portion 123 side of the light flux controlling member 121. Note that, in the cross section passing through the central axis CA of the light flux controlling member 120, the shape of the second incident surface 122a may be a curved line convex outward (side away from the central axis LA) or a straight line.

  In the present embodiment, in the cross section passing through the central axis CA of the light flux controlling member 120, the direction from the light emitting surface of the light emitting element 110 or its extension line to the end of the second incident surface 122a on the emitting portion 123 side is The distance and the distance in the direction of the central axis CA from the light emitting surface of the light emitting element 110 or its extension line to the end of the first total reflection surface 121b on the emission part 123 side are substantially the same, but they are different. Also good. However, these are preferably the same from the viewpoint of the light distribution characteristics of the light flux controlling member 120. That is, in the light flux controlling member 120, the end of the second incident surface 122a of the second convex portion 122 on the exit portion 123 side is substantially the same as the end of the first total reflection surface 121b of the first convex portion 121 on the exit portion 123 side. Preferably they are at the same height.

  On the other hand, the second total reflection surface 122b is a surface for reflecting at least a part of the light incident from the second incident surface 122a toward the emission part 123 side of the light flux controlling member 120. The second total reflection surface 122b is a rotationally symmetric surface with the central axis CA as a center, and is a surface extending from the light emitting element 110 side toward the outer edge side of the emission portion 123 of the light flux controlling member 120. The second total reflection surface 122b is also a surface constituting the outer peripheral surface of the light flux controlling member 120. The distance between the second total reflection surface 122b and the central axis CA of the light flux controlling member 120 is gradually increased from the light emitting element 110 side toward the light emitting portion 123 side of the light flux controlling member 120. Note that, in the cross section passing through the central axis CA of the light flux controlling member 120, the shape of the second total reflection surface 122b may be a curved curve convex outward (side away from the central axis LA) or a straight line. . Here, as shown in FIG. 3, a flange portion 125 may be disposed between the outer edge of the second total reflection surface 122 b on the emission portion 123 side and the outer edge of the emission portion 123.

  In addition, the output part 123 is disposed on the opposite side of the first convex part 121 and the second convex part 122, enters the light beam control member 120 from the first incident surface 121a, and directly reaches the output part 123, and A region for emitting the light reflected by the first total reflection surface 121b, the light incident on the second incident surface 122a and directly reaching the output portion 123, and the light reflected by the second total reflection surface 122b It is. In the present embodiment, the emitting portion 123 is a circular plane centered on the central axis CA, and is disposed so as to intersect the central axis CA perpendicularly.

Here, as shown in FIG. 4, in the light emitting device 100 of the present embodiment, when various lengths in a cross section passing through the central axis CA of the light flux controlling member 120 are defined as follows, the following formula (A ) To (E) are satisfied.
z: Width of the light emitting surface of the light emitting element 110 a: Maximum width in a direction orthogonal to the central axis CA of the first convex portion 121 b: From the light emitting surface of the light emitting element 110 to the end of the first total reflection surface 121a on the emitting portion 123 side. Distance in the central axis CA direction (in the present embodiment, the same distance as the distance in the central axis CA direction from the light emitting surface of the light emitting element 110 to the end of the second incident surface 122a on the emitting portion 123 side)
c: Width in the direction orthogonal to the central axis of the first incident surface 121a d: Distance between the first incident surface 121a and the light emitting surface of the light emitting element 110 e: Minimum distance between the first convex portion 121 and the second convex portion 122 h: Height of first total reflection surface 121b in optical axis CA direction i: Height of second total reflection surface 122b in optical axis CA direction

(A) 0.15z ≦ (a + 2e) ≦ 1.7z
(B) b ≧ z
(C) 0.15z ≦ c <z
(D) 0 <d ≦ 0.7b
(E) i> h

Hereinafter, each formula will be described.
Formula (A) Formula (A) is a formula that represents the relationship between the inner diameter (a + 2e) of the annular second convex portion 122 and the width z of the light emitting surface of the light emitting element 110. FIG. 5 shows a graph (simulation result) comparing the luminous intensity distribution of a light-emitting device for verification that satisfies the above-described formula (A) and the luminous intensity distribution of a comparative light-emitting device that does not satisfy the above-described formula (A). .

  Note that the light flux controlling member in the light emitting device for verification has the same structure as the light flux controlling member 120 of the present embodiment, except that the first convex portion is not provided. FIG. 6 shows a cross-sectional view of a light-emitting device for verification. As shown in FIG. 6, the light flux controlling member 120 ′ in the light emitting device for verification has a second convex part 122 including a second incident surface 122 a and a second total reflection surface 122 b, and an emitting part 123. Moreover, in the said light-emitting device, although said formula (A) and (B) are satisfy | filled, since light flux control member 120 'does not have a 1st convex part, the requirements of said formula (C)-(E) are I don't have it. As described above, the distance from the light emitting surface of the light emitting element 110 to the end of the first total reflection surface 121b on the emission part 123 side is b. In this embodiment, the distance is the light emitting surface of the light emitting element 110. Is the same as the distance in the direction of the central axis CA from the second incident surface 122a to the end portion on the emission portion 123 side. Therefore, in the light-emitting device for verification, the distance in the central axis CA direction to the end of the second incident surface 122a on the emission unit 123 side is handled as b. On the other hand, a light beam control member having the same shape as the light beam control member of the light-emitting device for verification and not satisfying the above formulas (A) and (B) was used for the comparative light-emitting device.

  Further, the luminous intensity distribution of FIG. 5 indicates the luminous intensity (relative intensity) of light emitted from the light emitting device 100 in the range of the optical axis LA ± 90 °, where the angle of light emitted in the direction of the optical axis LA of the light emitting element 110 is 0 °. Are plotted.

  In the light emitting device for spotlight, it is desired that the light condensing property is high, and it is desired that only the relative intensity near the optical axis LA is high. On the other hand, as shown in FIG. 5, when the value represented by the above (a + 2e) is larger than 1.7z, the width of the region having the relative intensity of 0.5 tends to be widened. Further, the relative intensity in the region of the optical axis LA ± 20 ° or more (the relative light intensity with respect to the maximum light intensity of the light distribution characteristic outside the target irradiated region) is relatively high. If the inner diameter of the second convex portion 122 of the light flux controlling member 120 becomes excessively large, the light distribution characteristic of the light incident on the second convex portion 122 is not sufficiently controlled, and light traveling outward from the target irradiated region It increases and the light collecting property decreases. On the other hand, when the inner diameter of the second convex portion 122 of the light flux controlling member 120 becomes excessively small, the outgoing light emitted from the light emitting element 110 at a small angle with respect to the optical axis LA is likely to be incident from the second incident surface 122a. As a result, the amount of light that should be reflected by the second total reflection surface 122b increases, and the second total reflection surface 122b is positioned upward (the light emitting element 110) in order to narrow the light incident on the second convex portion 122. Need to be expanded in a direction away from However, the dimension of the light flux controlling member 120 in the direction along the optical axis LA is limited. Therefore, when the second total reflection surface 122b cannot be enlarged, only the second total reflection surface 122b of the second convex portion 122 controls the light distribution characteristics of much light emitted from the light emitting element 110. This is difficult and the light condensing performance is reduced. On the other hand, when the above (a + 2e) satisfies the above formula (A), the width of the region where the relative intensity is 0.5 is narrowed, and the relative intensity in the region of the optical axis LA ± 20 ° or more is also reduced. .

Formula (B) The formula (B) is a distance from the light emitting surface of the light emitting element 110 to the end of the first total reflection surface 121b on the emission part 123 side (in the present embodiment, the second from the light emitting surface of the light emitting element 110). It is an expression representing the relationship between the distance (b) that is the same as the distance in the central axis CA direction to the end of the incident surface 122a on the emission part 123 side, and the width z of the light emitting surface of the light emitting element 110. FIG. 7 shows a graph (simulation result) comparing the luminous intensity distribution of a light-emitting device for verification that satisfies the above-described formula (B) and the luminous intensity distribution of a comparative light-emitting device that does not satisfy the above-described formula (B). . Note that the light-emitting device for verification and the light-emitting device for comparison used in the simulation of the above formula (A) were used for the simulation. FIG. 7 is a plot of the relative intensity of light in the same manner as in FIG.

  As shown in FIG. 7, when the value represented by b described above is smaller than the width z of the light emitting surface of the light emitting element 110, the relative intensity in the region of the optical axis LA ± 20 ° or more increases. When the value represented by b is decreased, the light reaching the second total reflection surface 122b (and the first total reflection surface 121b when the first convex portion 121 is provided) decreases, and the light from the light emitting element 110 is reduced. Most of the emitted light is emitted from the emission unit 123 without passing through the first total reflection surface 121b and the second total reflection surface 122b. As a result, the light condensing property of the light emitting device 100 is lowered. On the other hand, when the light emitting device 100 satisfies the above formula (B), more light reaches the first total reflection surface 121b and the second total reflection surface 122b, and these are easily reflected in a desired direction. Therefore, the light which goes outside the target irradiated area is reduced.

Formula (C) Formula (C) is a formula representing the relationship between the width c of the first incident surface 121 a of the first convex portion 121 of the light flux controlling member 120 and the width z of the light emitting surface of the light emitting element 110. . FIG. 8 is a graph (simulation result) comparing the luminous intensity distribution of the light-emitting device of the present embodiment that satisfies the above-described formula (C) and the luminous intensity distribution of a comparative light-emitting device that does not satisfy the above-described formula (C). Indicates. Note that the light-emitting device for comparison has the same configuration as that of the light-emitting device of this embodiment, and does not satisfy only the equation (C) among the above-described equations (A) to (E). What satisfy | filled A), (B), (D), and (E) was used. FIG. 8 is a plot of the relative intensity of light in the same manner as in FIG.

  As shown in FIG. 8, when the width c of the first incident surface 121a is equal to or larger than the width z of the light emitting surface of the light emitting element 110, the width of the region having a relative intensity of 0.5 is increased. Further, the relative intensity in the region of the optical axis LA ± 20 ° or more is also increased. When the width of the first incident surface 121a becomes excessively large, light emitted from the vicinity of the outer periphery of the light emitting surface of the light emitting element 110 also enters from the first incident surface 121a. However, it is difficult to control the light distribution characteristics of all the light with only the first total reflection surface 121b of the first convex portion 121, and the light-collecting property of the light-emitting device is lowered, so that it is outside the target irradiated region. Increasing light. On the other hand, when the light emitting device 100 satisfies the above formula (C), the light emitted from the light emitting element 110 enters the first convex portion 121 and the second convex portion 122. And since the light distribution characteristic is appropriately adjusted by the first total reflection surface 121b, the second total reflection surface 122b, and the like, the light condensing property is improved.

-About Formula (D) Formula (D) is the distance b from the light emission surface of the above-mentioned light emitting element 110 to the output part 123 side edge part of the 1st total reflection surface 121a, and the light emitting element 110 from the 1st incident surface 121a. It is a formula showing the relationship with the distance d to the light emitting surface. FIG. 9 is a graph comparing the luminous intensity distribution of the light-emitting device of the present embodiment that satisfies the above-described formula (D) and the luminous intensity distribution of a comparative light-emitting device that does not satisfy the above-described formula (D) (simulation result). Indicates. Note that the comparative light-emitting device has the same configuration as that of the light-emitting device of the present embodiment and does not satisfy only the formula (D) among the above-described formulas (A) to (E). ) To (C), and those satisfying (E) were used. FIG. 9 is a plot of the relative intensity of light in the same manner as in FIG.

  As shown in FIG. 9, when the distance d from the first incident surface 121a to the light emitting surface of the light emitting element 110 exceeds 0.7b, the width of the region having a relative intensity of 0.5 becomes wide. When the distance d from the first incident surface 121a to the light emitting surface of the light emitting element 110 increases, the light emitted from the light emission center or the like of the light emitting element 110 cannot enter the first convex portion 121 and the second convex portion 122 Incident light from the second incident surface 122a increases. In this case, since light emitted from a wide range of light emitting surfaces of the light emitting element 110 reaches the second total reflection surface 122b, light is incident on various points from a certain point on the second total reflection surface 122b. And it is difficult to totally reflect all of the light in the target direction, and as a result, the light collecting property is lowered. On the other hand, if the distance d from the first incident surface 121a to the light emitting surface of the light emitting element 110 is 0.7b or less, the light emitted from the light emission center or the like of the light emitting element 110 satisfies the above formula (D). Since the light is incident on the first convex portion 121 before the light spreads, it is possible to appropriately control the light distribution of these lights. As a result, the light condensing property of the light emitting device 100 is increased.

About Formula (E) Formula (E) is a formula representing the relationship between the height h of the first total reflection surface 121b in the direction of the central axis CA and the height i of the second total reflection surface 122b in the direction of the central axis CA. It is. When the height i of the second total reflection surface 122b is decreased, the light incident from the second incident surface 122a is not reflected by the second total reflection surface 122b, but is easily emitted from the emission unit 123. Lightness is reduced. On the other hand, when the height i of the second total reflection surface 122b is sufficiently higher than the height h of the first total reflection surface 121b, the light collecting property is improved.

-About other specification Moreover, it is preferable that the light beam control member 120 of this Embodiment satisfies the following formula | equation (F) for the value represented by the above-mentioned e.
(F) 0 ≦ e ≦ (1/3) a
The above formula (F) is obtained by calculating the gap e between the first convex portion 121 and the second convex portion 122 of the light flux controlling member 120 and the maximum width in the direction orthogonal to the central axis CA of the first convex portion 121 of the light flux controlling member 120. It is an expression representing the relationship. In the present embodiment, the first convex part 121 and the second convex part 122 may be arranged without a gap or may be arranged with a certain gap. However, when the gap e between the first convex portion 121 and the second convex portion 122 is increased, the light traveling outward from the target irradiated region increases. Therefore, it is preferable to satisfy the above formula (F).

Furthermore, light flux controlling member 120 of the present embodiment satisfies the following formula (G), where f is an angle formed between second incident surface 122a and a line parallel to central axis CA of light flux controlling member 120. It is preferable.
(G) 0 ° ≦ f ≦ 15 °
If the angle f exceeds 15 °, it is necessary to extend the second total reflection surface 122b upward. Therefore, from the viewpoint of reducing the size of the light flux controlling member 120, it is preferable to satisfy the above formula (G).

Furthermore, the light emitted from the outermost periphery of the light emitting surface of the light emitting element 110, incident on the light flux controlling member 120 from the second incident surface 122a, and reflected by the second total reflection surface 122b toward the emitting portion 123 side is emitted from the emitting portion 123. When the angle formed between the traveling direction of the light when emitted and the line parallel to the central axis of the light flux controlling member 120 is g (not shown), it is preferable to satisfy the following formula (H).
(H) 0 ° ≦ g ≦ 15 °
The above expression (H) is an expression for specifying the emission direction of the light emitted from the outermost periphery of the light emitting surface of the light emitting element 110 from the light emitting portion 123. The angle represented by g is adjusted by the angle and height of the second total reflection surface 122b. By arranging the second total reflection surface 122b so as to satisfy the above formula (H), the light emitting device 100 is provided. The light condensing property is improved.

-About the optical path in a light-emitting device Next, with reference to FIGS. 10-12, the optical path of the light of this Embodiment is demonstrated. 10A, FIG. 11A, and FIG. 12A are optical path diagrams of light from the light emitting element 110 of the light emitting device 100 of the present embodiment. On the other hand, FIG. 10B, FIG. 11B, and FIG. 12B are optical path diagrams of light from the light emitting element 510 of the comparative light emitting device 500 in which the light flux controlling member does not have the first convex portion 121. Note that the comparative light-emitting device 500 includes a light-emitting element 510 and a light flux control member 520 that controls the light distribution characteristics of light emitted from the light-emitting element 510. In addition, the light flux controlling member 520 includes an incident recess 521 in which light is incident, a total reflection surface 522 that reflects at least part of the light incident from the incident recess 521, light incident from the incident recess 521, and the total reflection surface 522. And an emission part 523 for emitting the light reflected.

In the comparative light emitting device 500, as shown in FIG. 10B and FIG. 11B, the light emitted from the light emission center of the light emitting element 510 is substantially parallel to the optical axis LA, and around the light emission center of the light emitting element 510. The light emitted from the incident surface enters from the top surface of the incident recess 521. Then, they proceed as they are in the light beam control member 520 and are emitted from the emission part 523.
In the comparative light emitting device 500, the distance between the light emitting surface of the light emitting element 510 and the incident concave portion 521 of the light flux controlling member 520 is relatively long. Therefore, the light emitted from the light emitting element 510 spreads to some extent and enters the light flux controlling member 520 (incident recess 521). Therefore, the light emitted from the emitting portion 523 is likely to be separated from the optical axis LA, and the light collecting property is likely to be reduced. Further, light that enters from the top surface of the incident concave portion 521 and directly reaches the emission portion 523 is emitted without being controlled in the direction of the total reflection surface 522, and thus tends to be directed toward the outside of the target irradiated region.

On the other hand, in the light emitting device 100 according to the present embodiment, as shown in FIGS. 10A and 11A, the light emitted from the light emission center of the light emitting element 110 has a small angle with respect to the optical axis LA, and the light emitting element. Light emitted from around the light emission center 110 is incident from the first incident surface 121 a of the first convex portion 121. Then, they proceed as they are in the light flux controlling member 120 and are emitted from the emission part 123.
In the light emitting device 100 of the present embodiment, the distance between the light emitting surface of the light emitting element 110 and the first incident surface 121a of the first convex portion 121 of the light flux controlling member 120 is short. Therefore, before the light emitted from the light emitting element 110 spreads, it enters the light flux controlling member 120 (first incident surface 121a). Therefore, the light emitted from the emission part 123 is likely to approach the optical axis LA as compared with the light emitting device 500 for comparison, and the light collecting property tends to be good.

  In the comparative light emitting device 500, as shown in FIG. 12B, light (broken line) having a large angle with respect to the optical axis LA out of the light emitted from the light emission center of the light emitting element 510 is incident from the side surface of the incident recess 521. To do. Then, the light is reflected by the total reflection surface 522 toward the emission part 523 and is emitted from the emission part 523. Furthermore, the light (solid line) emitted from the outermost periphery of the light emitting surface of the light emitting element 500 also enters the light beam control member 520 from the side surface of the incident recess 521 and is reflected by the total reflection surface 522 as shown in FIG. 12B. The light is emitted from the emission part 523. That is, in the comparative light emitting device 500, the traveling direction of the light emitted from the light emission center of the light emitting element 510 and the light emitted from the outermost periphery of the light emitting element 510 is controlled by one total reflection surface 522. . However, it is difficult to control such light to be emitted from the emitting portion 523 substantially parallel to the optical axis LA by one total reflection surface 522, and the angle formed by a part of the light and the optical axis LA becomes large. It was easy.

  On the other hand, in the light emitting device 100 of the present embodiment, as shown in FIG. 12A, the light (broken line) having an angle with respect to the optical axis LA among the light emitted from the light emission center of the light emitting element 110 is the first. Incident from the incident surface 121a. Then, the light is reflected from the first total reflection surface 121 b of the first convex part 121 toward the emission part 123 and emitted from the emission part 123. 12A, light (solid line) emitted from the outermost periphery of the light emitting surface of the light emitting element 110 is incident from the incident surface 122a of the second convex portion 122 of the light flux controlling member 120. Then, the light is reflected by the second total reflection surface 122 b of the second convex part 122 and is emitted from the emission part 123. That is, in the light emitting device 100 of the present embodiment, the light distribution characteristics of the light emitted from the light emission center of the light emitting element 110 are controlled by the first convex portion 121 and emitted from the vicinity of the outer periphery of the light emitting surface of the light emitting element 110. For the emitted light, the light distribution characteristics are controlled by the second convex portion 122. Therefore, as shown in FIG. 12A, the angle formed between the light emitted from the emitting portion 123 and the optical axis LA can be reduced.

(effect)
As described above, in the light emitting device 100 according to the present embodiment, the light emitted from the light emission center of the light emitting element 110 and the peripheral edge thereof controls the light distribution characteristics by the first convex portion 121, and the light emission of the light emitting element 110. The light emitted from the vicinity of the outermost periphery of the surface controls the light distribution characteristics by the second convex portion 122. At this time, since the first convex portion 121 and the second convex portion 122 have a predetermined shape (for example, satisfy the above formulas (A) to (C) and (E)), the first convex portion 121 and the second convex portion 121 The light distribution characteristics of the light incident on the two convex portions 122 can be sufficiently controlled.

  Moreover, in the light emitting device 100 of the present embodiment, the distance between the light emitting element 110 and the first incident surface 121a of the first convex portion 121 of the light flux controlling member 120 is sufficiently short (satisfying the above formula (D)). Therefore, the light distribution characteristics of the light incident on the light flux controlling member 120 can be sufficiently controlled.

  From the above, according to the light emitting device 100 of the present embodiment, it is possible to brightly illuminate only a specific range of the irradiated surface without increasing the size of the light emitting device 100.

[Embodiment 2]
Next, Embodiment 2 will be described. FIG. 13 is a diagram illustrating the light-emitting device of the second embodiment. 13A is a plan view of the light emitting device 200 according to Embodiment 2, FIG. 13B is a front view of the light emitting device 200, FIG. 13C is a bottom view of the light emitting device 200, and FIG. 13D is the light emitting device 200. FIG. 13E is a cross-sectional view taken along line AA shown in FIG. 13A.

  As illustrated in FIG. 13, the light emitting device 200 according to the second embodiment includes a light emitting element 110 and a light flux controlling member 220. The light emitting device 200 is different from the light emitting device 100 of the first embodiment in the shape of the emission part of the light flux controlling member 220. FIG. 14 shows a cross-sectional view through the central axis CA of the light flux controlling member 220 of the second embodiment. In addition, about the structure same as the light-emitting device 100 of Embodiment 1, the same number is attached | subjected and description is abbreviate | omitted.

  The light flux controlling member 220 of the present embodiment includes a first convex portion 121 disposed so as to face the light emitting element, a second convex portion 122 disposed so as to surround the first convex portion 121, and the first convex portion 121. And a light emitting part 223 formed on the opposite side of the first convex part 121 and the second convex part 122.

  The emission part 223 of the present embodiment is incident on the light flux controlling member 220 from the first incident surface 121a disposed on the opposite side of the first convex part 121 and the second convex part 122, and reaches the direct emission part 223. The light, the light reflected by the first total reflection surface 121b, the light incident on the second incident surface 122a and directly reaching the emission unit 223, and the light reflected by the second total reflection surface 122b are emitted. It is an area for.

  The emitting portion 223 of the present embodiment includes a concave portion 223 ″ disposed so as to be concave along the central axis CA of the light flux controlling member 220 and on the light emitting element 110 side. The shape of the concave portion 223 ″ is particularly The shape is not limited, and may be a columnar shape or a truncated cone shape. In the light flux controlling member 220 of the present embodiment, light is emitted not only from the surface 223 ′ opposite to the first convex portion 121 and the second convex portion 122 but also from the bottom surface 223 a and the side surface 223 b of the concave portion 223 ″.

(effect)
Also in the light emitting device 200 of the present embodiment, the light emitted from the light emission center of the light emitting element 110 and its peripheral part controls the light distribution characteristics by the first convex part 121, and is near the outermost periphery of the light emitting surface of the light emitting element 110. The light emitted from the second convex portion 122 controls the light distribution characteristics. At this time, since the first convex portion 121 and the second convex portion 122 have a predetermined shape (for example, satisfy the above formulas (A) to (C) and (E)), the first convex portion 121 and the second convex portion 121 The light distribution characteristics of the light incident on the two convex portions 122 can be sufficiently controlled.

  Moreover, in the light-emitting device 200 of this Embodiment, the distance of the light emitting element 110 and the 1st entrance surface 121a of the 1st convex part 121 of the light beam control member 220 is sufficiently close (the above-mentioned formula (D) is satisfied). Therefore, the light distribution characteristics of the light incident on the light flux controlling member 220 can be sufficiently controlled.

  From the above, according to the light emitting device 200 of the present embodiment, it is possible to brightly illuminate only a specific range of the irradiated surface without increasing the size of the light emitting device 200.

[Embodiment 3]
Next, Embodiment 3 will be described. FIG. 15 illustrates the light-emitting device of Embodiment 3. 15A is a plan view of the light emitting device 300 according to Embodiment 3, FIG. 15B is a front view of the light emitting device 300, FIG. 15C is a bottom view of the light emitting device 300, and FIG. 15D is the light emitting device 300. FIG. 15E is a cross-sectional view taken along line AA shown in FIG. 15A.

  As shown in FIG. 15, the light emitting device 300 of the present embodiment includes a light emitting element 110 and a light flux controlling member 320. The light emitting device 300 is different from the light emitting device 100 of the first embodiment in the shape of the emission part of the light flux controlling member 320 and the shape of the first incident surface of the first convex part. FIG. 16 shows a cross-sectional view through the central axis CA of the light flux controlling member 320 of the third embodiment. In addition, about the structure same as the light-emitting device 100 of Embodiment 1, the same number is attached | subjected and description is abbreviate | omitted.

  The light flux controlling member 320 of the present embodiment includes a first convex portion 321 disposed so as to face the light emitting element, a second convex portion 122 disposed so as to surround the first convex portion 321, and the first convex portion 321. And a light emitting portion 323 formed on the opposite side of the first convex portion 321 and the second convex portion 122.

  In the present embodiment, the first convex portion 321 is a columnar or truncated cone-shaped member arranged along the central axis of the light flux controlling member 320 and projecting to the light emitting element 110 side. About the 1st total reflection surface 121b which comprises the side surface of a stand, it is the same as that of the 1st total reflection surface 121b of Embodiment 1. FIG.

  On the other hand, the first incident surface 321 a constituting the top surface of the first convex portion 321 having a columnar shape or a truncated cone shape is a surface on which light emitted from the light emitting element 110 is incident, and is a position facing the light emitting element 110. Is arranged. The first incident surface 321a is a circular surface centered on the central axis CA and arranged to intersect the central axis CA of the light flux controlling member 320 perpendicularly, and includes a plurality of lens surfaces. The shape of the lens surface is not particularly limited, and may be a concave lens surface or a convex lens surface. In the present embodiment, it is a convex lens surface. Further, the size of each lens surface is not particularly limited, and is appropriately selected according to desired optical characteristics.

  On the other hand, the emission part 323 of the light flux controlling member 320 of the present embodiment is incident on the light flux controlling member 320 from the first incident surface 321a disposed on the opposite side of the first convex part 321 and the second convex part 122, The light that has directly reached the exit portion 323, the light that has been reflected by the first total reflection surface 121b, the light that has entered the second entrance surface 122a and has reached the exit portion 323, and the second total reflection surface 122b Is an area for emitting the reflected light.

  The emitting portion 323 according to the present embodiment includes a recess 323 ″ disposed so as to be recessed along the central axis CA of the light flux controlling member 320 and on the light emitting element 110 side. The shape of the recess 323 ″ is particularly special. The shape is not limited, and may be a columnar shape or a truncated cone shape. In the light flux controlling member 320 of the present embodiment, light is emitted not only from the surface 323 ′ opposite to the first convex portion 321 and the second convex portion 122 but also from the bottom surface 323 a and the side surface 323 b of the concave portion 323 ″.

  The bottom surface 323a of the recess 323 ″ includes a plurality of lens surfaces. The shape of the lens surface is not particularly limited, and may be a concave lens surface or a convex lens surface. In the present embodiment, a convex lens is used. Further, the size of each lens surface is not particularly limited, and is appropriately selected according to desired optical characteristics.

(effect)
Also in the light emitting device 300 of the present embodiment, the light emitted from the light emission center of the light emitting element 110 and its peripheral part controls the light distribution characteristics by the first convex part 321, and is near the outermost periphery of the light emitting surface of the light emitting element 110. The light emitted from the second convex portion 122 controls the light distribution characteristics. At this time, since the first convex part 321 and the second convex part 122 have a predetermined shape (for example, satisfy the above-mentioned formulas (A) to (C) and (E)), the first convex part 321 and the second convex part 321 The light distribution characteristics of the light incident on the two convex portions 122 can be sufficiently controlled.

  Further, in the light emitting device 300 of the present embodiment, the distance between the light emitting element 110 and the first incident surface 321a of the first convex portion 321 of the light flux controlling member 320 is sufficiently short (satisfying the above formula (D)). Therefore, the light distribution characteristics of the light incident on the light flux controlling member 320 can be sufficiently controlled.

  Furthermore, in the light emitting device 300 of the present embodiment, the first incident surface 321a and the bottom surface 323a of the recess 323 ″ of the emitting portion 323 include a plurality of lens surfaces. Therefore, the light incident on the first incident surface 321a The traveling direction and the traveling direction of the light emitted from the emitting portion 323 can be finely controlled.

  From the above, according to the light emitting device 300 of the present embodiment, it is possible to brightly illuminate only a specific range of the irradiated surface without increasing the size of the light emitting device 300.

[Modification]
In the light emitting device of the present invention, the shape of the first incident surface of the first convex portion of the light flux controlling member is not limited to a flat shape or a shape including a plurality of lens surfaces as shown in the first to third embodiments. FIG. 17 shows a light flux controlling member 420 according to a modification of the light emitting device of the second embodiment. FIG. 17 is a cross-sectional view of the light flux controlling member 420 passing through the central axis CA. In addition, about the structure same as the light beam control member 220 of the light-emitting device of Embodiment 2, the same number is attached | subjected and description is abbreviate | omitted.

  As shown in FIG. 17, the first incident surface 421a of the first convex portion 421 of the light flux controlling member 420 according to the modified example has an annular groove portion 421a 'centered on the central axis CA. The annular groove 421 a ′ is a triangular recess in a cross section passing through the central axis CA of the light flux controlling member 420. When the first incident surface 421a has an annular groove 421a ′, the light incident from the light emitting element (not shown) is incident on the light flux controlling member 420 and the light flux controlling member 420 is incident. It is possible to further subdivide the surface for totally reflecting the light. Therefore, the orientation characteristics of the light emitting device can be controlled more finely, and the light collecting effect can be further enhanced.

  Note that FIG. 17 shows the light flux controlling member 420 in which the emission surface 223 has the recess 223 ″, but the emission surface may be formed in a planar shape as in the first embodiment.

(Lighting device)
The above light-emitting device can be used for various lighting devices. The light emitting device can brightly illuminate only a specific area of the irradiated surface. Therefore, it is particularly useful for an illumination device for spot illumination. As illustrated in the schematic diagram of FIG. 18, the illumination device 440 for spot illumination can include a light emitting device 400 and an irradiated member 430 that is irradiated with light emitted from the light emitting device 400. .

  The light emitting device of the present invention can brightly illuminate a specific range of the irradiated surface and is relatively small in size. Therefore, the light emitting device of the present invention is very useful as, for example, a spotlight used indoors and outdoors.

110, 510, 810 Light emitting element 120, 220, 320, 420, 520, 820 Light flux controlling member 121, 321, 421 First convex portion 121a, 321a, 421a First incident surface 121b First total reflection surface 122 Second convex portion 122a Second incident surface 122b Second total reflection surface 123, 223, 323 Emitting portion 223 ", 323" Recess 430 Irradiated member 440 Illuminating device CA Central axis LA Optical axis 100, 200, 300, 400, 500, 800 Light emitting device

Claims (10)

A light-emitting device comprising: a light-emitting element; and a light flux control member that has the optical axis of the light-emitting element as a central axis and makes light emitted from the light-emitting element incident and controls and distributes the light distribution of the incident light. There,
The light flux controlling member is
A first incident surface on which light emitted from the light emitting element is incident; and a first total reflection surface that totally reflects a part of the light incident from the first incident surface, and facing the light emitting element. A first convex portion disposed;
A second incident surface on which light emitted from the light emitting element is incident; and a second total reflection surface that totally reflects at least a part of the light incident from the second incident surface, and surrounds the first convex portion. A second convex portion arranged as follows:
The first protrusion that emits light incident from the first incident surface and light reflected by the first total reflection surface, and light incident on the second incident surface and light reflected by the second total reflection surface. And a light emitting portion disposed on the opposite side of the second convex portion,
The first incident surface is disposed at a position facing the light emitting element so as to intersect the central axis of the light flux controlling member,
The first total reflection surface surrounds the central axis of the light flux controlling member, and the distance from the central axis is constant, or the distance from the central axis is gradually increased from the light emitting element side toward the emitting portion side. Arranged to be
The second incident surface surrounds the central axis of the light flux controlling member, and the distance from the central axis is constant, or the distance from the central axis gradually decreases from the light emitting element side toward the emitting portion side. Arranged as
The second total reflection surface surrounds the central axis of the light flux controlling member, and is arranged so that the distance from the central axis gradually increases from the light emitting element side toward the emitting portion side,
In a cross section passing through the central axis of the light flux controlling member,
The width of the light emitting surface of the light emitting element facing the light flux controlling member is z, the maximum width of the first convex portion in the direction orthogonal to the central axis is a, and the minimum distance between the first convex portion and the second convex portion. E, the distance in the central axis direction from the light emitting surface of the light emitting element or its extension line to the end of the first total reflection surface in the central axis direction, b, orthogonal to the central axis of the first incident surface The width of the direction is c, the distance between the first incident surface and the light emitting surface of the light emitting element is d, the height of the first total reflection surface in the central axis direction is h, and the height of the second total reflection surface is A light emitting device that satisfies the following formulas (A) to (E), where i is the height in the central axis direction.
(A) 0.15z ≦ (a + 2e) ≦ 1.7z
(B) b ≧ z
(C) 0.15z ≦ c <z
(D) 0 <d ≦ 0.7b
(E) i> h In a cross section passing through the central axis of the light flux controlling member,
The distance in the central axis direction from the light emitting surface of the light emitting element or its extension line to the light emitting side end of the first total reflection surface, and the second incident from the light emitting surface of the light emitting element or its extension line. The distance in the central axis direction to the emission part side end of the surface is the same,
The light emitting device according to claim 1. Further satisfying the following formula (F):
The light emitting device according to claim 1.
(F) 0 ≦ e ≦ (1/3) a In a cross section passing through the central axis of the light flux controlling member, when an angle formed by the second incident surface and a line parallel to the central axis is f, the following formula (G) is satisfied:
The light-emitting device as described in any one of Claims 1-3.
(G) 0 ° ≦ f ≦ 15 ° Light that is emitted from the outermost periphery of the light emitting surface of the light emitting element, is incident on the light flux controlling member from the second incident surface, and is reflected from the second total reflection surface toward the emitting portion is emitted from the emitting portion. When the angle formed between the traveling direction of the light and the line parallel to the central axis of the light flux controlling member is g, the following formula (H) is satisfied:
The light-emitting device as described in any one of Claims 1-4.
(H) 0 ° ≦ g ≦ 15 ° The light flux controlling member has a recess on the emission part side,
The emitting portion includes a bottom surface of the recess and a side surface of the recess.
The light emitting device according to any one of claims 1 to 5. The first incident surface has an annular groove centered on the central axis;
The groove is a triangular recess in a cross section including the central axis.
The light emitting device according to any one of claims 1 to 6. The emission part includes a plurality of lens surfaces,
The light emitting device according to any one of claims 1 to 7. The first incident surface includes a plurality of lens surfaces;
The light emitting device according to any one of claims 1 to 8. A light emitting device according to any one of claims 1 to 9,
A member to be irradiated with light emitted from the light emitting device;
A lighting device.